This invention relates to carrying bags and more particularly to a method and apparatus for applying and securing handles onto the carrying bags.
Carrying bags having U-shaped carrying handles are well known in the art. There are numerous types of processes and apparatus for forming the bags and for applying handles to the bags. Some of these apply the handles to either the outside or the inside of the mouth of the bag by welding or heat sealing operations. In most cases, two carrying handles are applied respectively to each of the two walls of the bag. In applying both handles, the process becomes quite complex. By using heat responsive materials in a heat sealing operation there occurs the problem of restricting the heat to only effect certain of the layers therebeneath. For example, in fastening two handles respectively to the two outer surfaces of the bags, a mandrel is generally inserted between the two inner surfaces of the bags to prevent the heat from sealing together the walls of the bag, as disclosed in U.S. Pat. No. 3,507,194, granted Apr. 21, 1970 to August Schwarzkopf. When applying the handles to the inner surfaces of the bag, it is necessary to utilize a non-weldable layer adhering to the inner side surfaces of the carrying handle strips as they are inserted inside the mouth of the bag.
Further complexities have arisen with prior art apparatus since they have generally attempted to apply the handles simultaneously with the formation of the bag itself. Such apparatus typically utilize a rolling process for forming the bags, and prior to the separation of the individual bag from the length of the bag tubing, the handles are applied. This complicates matters since it is therefore necessary to have expensive mechanism and apparatus to form slits or spaces which separates the walls of the bags to insert the handles.
Additionally, the prior art apparatus have generally been limited to utilizing only certain types of materials for the bags and handles. Most frequently, plastic bags and plastic handles are utilized. However, it is often required to form paper bags and apply either plastic or cardboard handles to the paper bags. Existing apparatus are generally designed for only one type of material and it is not possible to easily change the machinery to accommodate either plastic or paper bags.